On Wed, 5 Feb 2025 21:08:47 +0000 Prakash Sangappa <prakash.sangappa@xxxxxxxxxx> wrote: > The new syscall/API proposed was to provide per thread shared mapped > area(shared structure) that are allocated from memory pages that are pinned. > So the kernel could access it without the need for a copyin/copyout. > > The idea is that it would be helpful in places where we cannot take a page > fault in the kernel codepath. What places do we need to decided this in a critical path? If we follow my proposal, where we set NEED_RESCHED_LAZY on sched_tick when it interrupts user space, then it should all work out. I agree with Peter about not caring about system calls. If you can do a system call in a critical path, then just use futexes. The only reason I support system calls is for debugging. That's because I write into the trace_marker from user space to see if things are working, and that requires a system call. But once things are working, I'll make it not work for system calls too. -- Steve
